12results about How to "Increase the bandgap" patented technology

The invention discloses a Ni-BDC MOF / gamma-MnO2 composite photocatalyst material, a preparation method and application of the Ni-BDC MOF / gamma-MnO2 composite photocatalyst material in efficient catalysis of carbon dioxide reduction, Ni-BDC MOF has a two-dimensional sheet structure and Ni < 2 + > active sites for adsorbing CO2 and provides a framework for CO2 adsorption and reduction, gamma-MnO2 is added into the Ni-BDC MOF to form heterojunctions, and gamma-MnO2 components improve light absorption and enhance charge separation. The composite photocatalyst material prepared by the invention not only can effectively catalyze the reaction of reducing CO2 into CO and CH4 under visible light and conventional environmental conditions, but also does not need to use harmful solvents, and has better economic benefits and ecological benefits.

The invention relates to H2S detection, in particular to an aggregation-induced emission-based ratiometric fluorescence sensing system and application thereof.Penicillamine is used as a ligand to synthesize gold-copper nano-clusters (Pen-Au / CuNCs) and tetraphenylethylene modified hollow mesoporous silica (TPE-NH2-HMSNs) of an amino ligand, and the Pen-Au / CuNCs and the tetraphenylethylene modified hollow mesoporous silica are combined to successfully construct an efficient ratiometric fluorescence sensing platform (Au / CuNCs and HMSNs). The sensor is used for selectively detecting H2S, and two analysis methods of solution sensing and solid portable sensing are established. Compared with other methods for detecting H2S reported before, the method provided by the invention has a lower detection limit (0.147 [mu] M). In addition, a novel portable hydrogel bead fluorescence detection device is developed by utilizing color change, and quantitative visual detection of H2S is realized by combining with a smart phone.

The present invention discloses a ring-type elastic metamaterial structure with medium and low frequency vibration reduction characteristics, a bottom surface is provided on one side of a solid circular ring structure, and multiple layers of circular rings are arranged periodically from the inside to the outside along the radius direction of the solid circular ring structure on the bottom surface, a trunk portion is provided in the innermost circular ring, and four wedge-shaped blocks are arranged at intervals on the outer side of each layer of circular rings, and the trunk portion is connected to the wedge-shaped blocks on each layer of circular rings through four columnar structures to form a radial elastic structure, and the radial elastic structure extends outward from the innermost circular ring and is connected to the side wall of the outermost circular ring to form a ring-type elastic metamaterial structure with medium and low frequency vibration reduction characteristics. The present invention forms a partially hollowed structure by connecting the radial elastic structure with the solid circular ring structure, and can provide excellent vibration reduction characteristics in medium and low frequency environments.

The application discloses a compression-torsion coupling mechanism and a phononic crystal damping device with adjustable band gap, and belongs to the technical field of phononic crystal damping. The compression-torsion coupling mechanism comprises two plastic elastic plates arranged oppositely, the two plastic elastic plates are connected through a plurality of connecting rods, the connecting rods are connected with the corresponding plastic elastic plates through spherical hinges at two ends, electromagnetic coils are arranged on opposite surfaces of the two plastic elastic plates, the two electromagnetic coils are respectively connected with power supplies, and holes matched with tubular target structures are arranged on the plastic elastic plates. The phononic crystal damping device with adjustable band gap comprises a plurality of sleeves, the plurality of sleeves are used for being regularly and intervalled on the tubular target structure, at least one compression-torsion coupling mechanism is arranged between the two sleeves, the compression-torsion coupling mechanism is convenient to design and manufacture, the installation spacing of the phononic crystal damping unit can be changed through remote and reversible electromagnetic driving, and therefore the effect of adjustable band gap is achieved, and the operation is simple.

The present invention belongs to the field of piezoelectric catalysis technology, and specifically relates to an adenine / SDBS / UiO-66 composite catalyst, a preparation method and an application thereof. Adenine / UiO-66 (AD-U) material was synthesized by adding a connecting agent adenine, and then a surfactant (sodium dodecylbenzene sulfonate, SDBS) was introduced to prepare an adenine / SDBS / UiO-66 (AD-U-S) composite material. The optimized AD-U-S catalyst has an efficiency of up to 98% in degrading DCF in 30 minutes, which is 20 minutes earlier than the AD-U catalyst. Therefore, the AD-U-S catalyst has better piezoelectric response performance, a larger specific surface area and a higher charge transfer efficiency. The preparation conditions of the present invention are easy to control, environmentally friendly, simple in process, and good in operability. The obtained material has the characteristics of high catalytic efficiency, low energy consumption, high stability, and no secondary pollution.

The invention provides an epitaxial layer structure of a doped InSb film and a preparation process thereof, based on an MOCVD (Metal Organic Chemical Vapor Deposition) process, an InSb: Te layer and an InSb layer are periodically and alternately grown to form a doped InSb functional layer of a Hall element, the band gap of an InSb material can be increased, and the temperature coefficient of the Hall element of the InSb film is reduced; furthermore, according to the epitaxial layer structure and the preparation process provided by the invention, uniform doping can be realized, excessive Te doping can be avoided, and the defect density and the surface state density of the doped InSb functional layer can be reduced, so that the sensitivity of the InSb Hall element is improved, and the background noise of the Hall element is reduced. Besides, according to the epitaxial layer structure of the doped InSb film and the preparation process thereof provided by the invention, the growth processes, materials, thicknesses and the like of the buffer layer and the gradient layer are further improved, lattice mismatch between the substrate and the InSb film is slowed down, the dislocation density of the InSb film caused by mismatch is reduced, the InSb film with higher mobility can be grown, and the yield of the InSb film is improved. And therefore, higher sensitivity can be obtained on the Hall element.

The invention relates to the technical field of photo-assisted electro-catalysis, and discloses a modified molybdenum disulfide / carbon-based composite material and a preparation method and application thereof, and the modified molybdenum disulfide / carbon-based composite material comprises an entangled carbon-based material; low-defect MoS2 is embedded in the entangled carbon-based material and on the surface of the entangled carbon-based material; the surface of the entangled carbon-based material is partially coated with a hydrophilic polymer. The preparation method comprises the following steps: uniformly mixing the low-defect MoS2 and the entangled carbon-based material, adding a hydrophilic polymer solution, stirring at room temperature for 30 minutes, and drying to obtain the modified molybdenum disulfide / carbon-based composite material. The modified molybdenum disulfide / carbon-based composite material is used for photo-assisted electro-catalysis hydrogen production. According to the modified molybdenum disulfide / carbon-based composite material provided by the invention, the hydrophilic and hydrophobic properties are improved, and a larger contact area and a larger mass transfer rate are brought, so that the overall hydrogen production performance is obviously improved.

The invention relates to the technical field of perovskite quantum dots, in particular to a surface ligand precursor solution of blue-light perovskite quantum dots, which is prepared by the following steps: preparing a cesium / rubidium precursor and a zinc / lead halide precursor solution, quickly thermally injecting the cesium / rubidium precursor solution into the zinc / lead halide precursor solution, adding ethyl acetate, and performing centrifugal purification to obtain a coarse precipitate; and dropwise adding methylbenzene for dissolving, centrifuging and purifying to obtain quantum dot precipitates, and uniformly dispersing the quantum dot precipitates into normal octane to obtain the quantum dot. According to the blue-light perovskite quantum dot, rubidium and zinc are co-doped to form a more stable perovskite crystal form with halide ions, a surface ligand precursor solution of the blue-light perovskite quantum dot is formed, chloride ions, rubidium ions and zinc ions have higher tolerance factors, a more regular crystal structure is formed, the ion radius of rubidium is smaller than that of cesium, and the blue-light perovskite quantum dot is more stable. Quantum dot crystal lattices are shrunk after rubidium doping, Zn-Cl bonds are more stable than Pb-Cl bonds due to zinc doping, chloride ion vacancy defects are reduced, and the stability of the quantum dots is improved.

The application relates to a quantum dot preparation method and belongs to the technical field of quantum dot materials. The quantum dot preparation method comprises the following steps: dispersing original core quantum dots in a nonpolar solvent I to obtain original core quantum dot suspension I; mixing the original core quantum dot suspension I with a polar solvent containing doped cations to transfer the original core quantum dots to the polar solvent to obtain original core quantum dot suspension II; adding nonpolar solvent II and ligand solvent into the original core quantum dot suspension II to transfer the original core quantum dots to the nonpolar solvent II to obtain ligand-exchanged original core quantum dot suspension III; and mixing dispersing solvent, doped cation precursor solution and the original core quantum dot suspension III to perform cation exchange. The application cooperates the pretreatment process of ligand exchange with the liquid-phase cation exchange process, and tunes the optical performance of the core quantum dots.

The invention discloses a green and environment-friendly coating fluorescence enhancement method for CdTe QDs by silane surface hyperbranched polymerization modification, which comprises the following steps: synthesizing stable CdTe QDs by using water-soluble 3-MPA as a stabilizer through a simple solvothermal method; a P-APTEs (at) CdTe QDs compound with an ideal fluorescence enhancement effect is obtained by adding a small amount of APTEs into a quantum dot aqueous solution to carry out coating modification on the surfaces of the quantum dots, the fluorescence quantum yield is also obviously improved, the light absorption capacity of the compound is greatly enhanced, the utilization of the quantum dots to short-wave radiation is increased, and the fluorescence enhancement effect of the quantum dots is improved. Compared with the prior art, the CdTe QDs have the advantages that the CdTe QDs are modified, visible light with longer wavelength is emitted, the modified quantum dots show narrower FWHM, the fluorescence monochromaticity is improved, the fluorescence intensity of the modified CdTe QDs is enhanced by 20 times under the optimal effect, and the fluorescence quantum yield is increased by 153.79%.

The invention belongs to the technical field of semiconductor devices, and particularly discloses a high-electron-mobility transistor with an InGaN insertion layer and a double-barrier cap layer and a preparation method of the high-electron-mobility transistor. The high-electron-mobility transistor comprises a substrate, a nucleating layer, an AlGaN gradient buffer layer, a GaN channel layer, an InGaN insertion layer, an AlGaN barrier layer, a barrier protection layer, a double-barrier cap layer (an AlGaN layer, a GaN layer and an AlGaN layer) and a gate electrode which are sequentially arranged in a contact mode. Ohmic contact regions are arranged on the two sides of the AlGaN barrier layer and the barrier protection layer respectively and are electrically connected with the source electrode and the drain electrode respectively. By introducing the specific epitaxial layer combination and doping design, the distribution and control of two-dimensional electron gas are optimized, the confinement to electrons is increased, the output characteristic of the device is improved, the current collapse effect is inhibited, the leakage current is reduced, and the threshold voltage stability and switching characteristic of the device are improved.

The present invention belongs to the technical field of light-emitting diodes, and in particular, relates to a method for preparing a zinc oxide nanomaterial, comprising the steps of obtaining a lithium hydroxide solution and anhydrous zinc acetate; mixing and dissolving the anhydrous zinc acetate and the lithium hydroxide solution in an anhydrous and oxygen-free environment, and then performing a thermal reaction to separate and obtain the zinc oxide nanomaterial. The method for preparing the zinc oxide nanomaterial provided by the present invention uses lithium hydroxide and anhydrous zinc acetate as raw materials, obtains the zinc oxide nanomaterial by thermal reaction in an anhydrous and oxygen-free environment, and reasonably regulates the reaction raw materials and reaction condition parameters, so that the particle size of the obtained zinc oxide nanomaterial is 5 to 7 nanometers, the particle size is small, the dispersion stability is good, and the energy gap is wide, reaching 3.7 eV.